Method of making collapsible containers



Nov. 21, 1939. J. H. FRIDEN METHOD OF MAKING COLLAPSIBLE CONTAINERS priginal Filed April 30, 1936 Patented Nov. 21, 1939 UNITED STATES PATENT OFFICE I METHOD or MAKING COLLAPSIBLE CONTAINERS John H. Fridn, Mapiewood, N. 1., assignor to The Sun Tube Corporation,

Hillside, N. 1., a

corporation of .New Jersey August 12, 1939 3 Claims.

This invention relates to the production of an improved form of collapsible containen/particularly suited for the packaging of liquids, such as hair tonics, shampoos, rinses and the like. An important object of the invention has been to provide a novel method of producing a non-reflllable container that is attractive, inexpensive, light, non-bulky, sanitary and easily disposed of when empty. This is a division of my pending application, Serial No. 77,136,filed April 30, 1936, in which the novel container produced by my improved method is being claimed.

The improved method is adapted to produce a thin-walled, metal container by the extrusion of tin, lead, zinc, aluminum or other metal of readily extrudable character. One end of the container, through which its contents is intended to be discharged, is sealed by an integral portion of the metal that may be readily removed or punctured when the contents are to be used. A special construction is provided at this end to facilitate the production of a small discharge opening without the use of any tool or implement. The arrangement is such that the aperture produced is relatively fine so that none of the liquid contents will be spilled and no appreciable evaporation loss will take place so long as the contents are completely used up within a reasonable time after the package is opened. To discharge the contents the tube may either be shaken in an inverted position or the walls may simply be squeezed together to squirt out the liquid. The opposite end of the container may be wide open until it is filled and it may then be closed in anyconvenient way, as by folding and crimping or applying a clip, as is common in the packaging of tooth pastes and the like.

Other objects and advantagesof the invention will appear from the detailed description of an illustrative form of container and method of making the same which will now be given in conjunction with the accompanying drawing, in which:

Figures 1, 2 and 3 are schematic views illustrating in vertical section the die and punch used in producing the improved tube, the punch being indicated in different stages of its operation.

Figure 4 is an enlarged, longitudinal section through the end of a tube made in accordance with the invention. V

Figures 5 and 6 are views similar to Figure 4, showing the aperture partially and more completely formed, respectively, and Figure 7 is a perspective view of a finished tube through the metal of the closure.

withthe aperture forming stem indicated in dot and dash lines.

Referring now to Figures 4 to 7 of thedrawing, the preferred form of the container will first be explained. I It has a side wall l0, preferably cylindrical, formed of thin metal of a thickness comparable with that of the wall of an ordinary collapsible tube. Any readily extrudable metal or mixture or alloy of metals may be employed so long as the inner surface of the tube will not affect the intended contents. The end ll of the tube is wide open until it has been filled through this end, after which the wall is preferably simply pinched together and folded several times and crimped to provide a thoroughly liquid-tight seal. This type of closure, indicated at l2 in Figure 7, is well known and need not be explained in further detail.

The opposite end of the tube is. completely closed by metal integral with the side wall. The disc-like 'closure preferably has a flat, central portion i3 and a sloping portion [4 extending downwardly and outwardly toward the side wall. However, this may be varied, if desired. Preferably the thickness of the metal in the closure will be somewhat greater than in the wall It to lend greater stiffness to. the end of the tube. At the center of the portion IS a small stem or projection i5 extends in an axial direction. This projection is preferably, though not necessarily,

cylindrical in cross-section and of a diameter several times greater than the thickness of the metal of portion IS. The purpose of the projection is to enable the formation of a small aperture through the portion i 3 without the use of any implement. For this purpose the stem i5 is simply rocked back and forth a few times .and it will 'be found that the metal of the portion I3 will shear right around the base of the stem. The

metal will first give way at one side of the stem,

as shown in Figure 5, and then the aperture is made larger as the stem is folded over into the position of Figure 6. It will be clear that the desired result would not be achieved if the stem l5 were made too slender in proportion to the thickness of portion i 3 since then the shear would take place at the base of the stem, through its own cross-section, rather than around the stem, Accordingly, the diameter of the stem should be somewhat greater than the thickness of portion l 3 and 'pref-,

.erably several times this thickness. At the same time it should not be too large as then the discharge opening would be made larger than desired. To facilitate formation of the aperture in the way mentioned, the portion It may, if desired, be made slightly thinner than the portion id. The latter will in that case supply the desired stiffness to the end of the tube.

The stem l5 need not becompletely removed This may be done several times before the stem becomes completely severed. As indicated at IS, in Fig. 6, a narrow neck of metal still unites the stem with the tube when the stem is first bent over and this will stand several bendings before it snaps. In fact, however, the opening provided by the stem may be so small that little loss by evaporation will ordinarily take place within a reasonable time even though no efiort is made to seal the opening after it has once beenmade. A relatively quick discharge may be eifected, when desired, by squeezing the tube even though the opening is quite small.

Referring now to Figures 1 to 3, there is illustrated several stages in the preferred mode of production of the improved tube. In general the method consists in applying adequate pressure to an extrudable slug of material by means of a blunt-ended punch while the slug is in a suitable die. The die has a small axial opening at its center to permit a portion of the metal to be extruded downwardly in line with the punch. At the same time a suitable clearance is provided between the punch and the slug receiving recess of the die so that the major portion of the metal of the slug will be extruded upwardly along the punch. There is a combination, therefore, of two different types of extrusion effected by the blunt.

ended punch.

In carrying out the process a slug 20 of suitable size is deposited in the recess 2| of a die 22. The wall 23 of the recess is preferably formed with a slight taper inwardly toward the bottom while the bottom of the die has an annular sloping portion 25 surrounding a central, fiat portion 25.

This corresponds with the shape desired at the top of the finished tube. At the center of the fiat portion 25 of the die bottom there is provided a small aperture 26 of a diameter equal to that of the stem i5 of the finished tube. This aperture extends completely through the die but its lower portion is preferably enlarged considerably, as indicated at 26a. The slender portion of the aperture need only be slightly deeper than the length of the desired stem iii. A plunger 21 operating within the enlarged portion 26a of the die aperture has a slender extension 28 fitting snugly within the lower portion of the slender section of the aperture. Any suitable means, of a character known in the art, may be provided for shifting the plunger axially within the die aperture.

During the extrusion operation the plunger will remain in the position indicated in Figures 1 and 2. At this time the top of the reduced portion 28' of the plunger forms a bottom to the die aperture against which the extruded metal will be forced and beyond which the metal cannot flow. The position of the plunger will, therefore, determine the length of the stem i5. If desired, its normal position may be made adiustable to vary the length of the stem. On completion of the extrusion operation the plunger is forced upwardly in the aperture to assist in ejecting the stem' and tube from the die;

diameter of the recess 2| so that the metal of the,

slug will not only be extruded downwardly into the aperture 26 but will also be extruded around the punch, through the passage between the punch and the wall 23, to form the wall ill of the tube. Any suitable mechanism well known in extrusion presses may be employed for operating the punch. This mechanism will preferably include some means, also well known, for swinging the punch'from its position in axial alinement with the die recess into a position enabling the discharge of the tube into a suitable channel for delivery to a conveyor, or the like. The punch is preferably formed with an axial opening 3| through which air may be blown to remove the tube from the punch at the appropriate time. A valve or closure member 32 serves to close the lower end of the punch during the extrusion operation, thus preventing accidental extrusion of metal into the air passage. A set-screw 38 limits the outward movement of the closure. It will be understood that the operation of the plunger 21 will be suitably timed to coincide with the withdrawal of the punch from the die and air will be blown through the punch as it is carried into the proper discharge position.

Should it be desired to make the central portion i3 at the end of the tube thinner than the portion i4, this may be done by forming the conical surface 34 on the punch at a slightly greater angle than the surface 26 of the die so that the passage between them will converge slightly toward the bottom. p

The tubes formed by the extrusion operation will be of somewhat irregular form at their open ends but'otherwise will be in completely finished condition. The only operation, therefore, actually required to produce a finished tube'is the removal of a small section or ring at the open end of the tube. This may be done, in a manner well known in the art, by mounting the tube on a rotating spindle and bringing a cutting edge against the tube at the appropriate point. If desired, the tube may be decorated with any chosen design and for this purpose any of the well brown coating and printing devices or machines used in the production of collapsible tubes 1'05 tooth paste and the like may be utilized.

While a preferred form of tube and a preferred method of producing the same have been described in considerable detail, it will be understood that various changes may be made in both the tube and the method without departing from the principles and scope of the invention. It will be understood that the terms and expressions used herein have been employed as terms of description and not of limitation.

What I claim is:

1. 'A method of producing a non-refillable container which comprises subjecting an imperforate slug of extrudable material to an extrusion pressure by means of a blunt-ended punch while the slug is in a die having a recess of slightly greater diameter than the punch, the die having an opening leading from the bottom of the recess, said opening being of such a small cross-sectional wardly as a. solid stem through said opening as well as upwardly around the punch at least in part by the squeezing action of the same portions of the punch.

2. A method of producing a collapsible tube which comprises squeezing an imperforate slugv the punch and being such as to cause simultaneous extrusion therethrough and around the 15 punch.

of extrudable material through a small aperture in the bottom of a die to form a solid stem and simultaneously causing said slug to extrude as a hollow tubular member in the opposite direction, at least in part by the squeezing action of the same portions of a punch and die, the passages through which the material is extruded to form the stem and tubular member respectively,-presenting substantially the same resistance to extrusion.

JOHN H. mm.

3. A method of producing a collapsible tube which comprises extruding an imperforate slug. 

